A limitation we ran into within the subaccount features, is that it does not support the use of custom user groups (CUG's). We have quite a few use cases where we would like to assign a campaign to a specific subset of the users within a subaccount, either by using the conditions or with an import file. This is currently not possible, and therefore, we have to create these campaigns on the root account level instead.
Enabeling the Custom User Group feature at subaccount level. Of course, when using an import file, Impact should filter out any users that are not existing within that subaccount.
